document.onmousemove = function (ev) {
	var e = ev || window.event;
	var div = document.getElementById('a1');
	div.innerHTML = "clientX: "+e.clientX + ",clientY:"+ e.clientY +
				"</br> screenX:"+ e.screenX+",screenY:" + e.screenY+
				"<br/> offsetLeft:"+a1.offsetLeft+",offsetTop:"+a1.offsetTop;
}